I only quickly glanced at the posts up to this point but I have a feeling people are chiming in without really looking at the battery graph that you posted . . .
View attachment 167610
Draw some lines up from the bars below to the upper graph and you can see some things . . .
1. In general your device is AWAKE most of the time. That's bad for battery . . . period . .
2. Your screen is on a lot during charging . . why is that?
3. When the screen is off during charging the charging rate is high (see the part between the 3rd and 4th yellow dashed lines I drew?).
4. Your mobile signal while charging is low in strength which will impact power consumption, PARTICULARLY if youre using the device while charging and you're not on wifi.
If the image you posted isn't typical of what's general use for you then ignore this post but taken at face value I think what needs to be addressed is the fact that for maximum charge speed one should reduce load on the battery while charging. If not . . then heat will be a factor and charging speed may be reduced to protect the battery from overheating.